Students

Prof John Nderitu and colleagues attending a workshop at The Nairobi National Museum

Principal CAVS welcome Gatugi Girls during their visit

Principal CAVS speaks to Gatugi Girls Sec. during their visit

Prof.Kiama the principal CAVS welcomes Gatugi Girls Sec. School.

Gfar Workshop at SeMis

CS Environment and Natural Resources Prof. Judi Wakhungu during handing over of Meteorological instruments to CAVS

The NPCK and Radboud University from The Netherlands partnered through a survey on 'Effectiveness of Networks in Seed Potato Sector Development in Kenya between March-April 2017

The NPCK and Radboud University from The Netherlands partnered through
a survey on 'Effectiveness of Networks in Seed Potato Sector
Development in Kenya between March-April 2017

Appreciating former Chairmen of the Department

The department of appreciated its former Heads of Department for their exemplary service on Thursday, 23rd November, 2017 front raw fro right Prof Michieka,Prof Mukunya,Prof Mutitu,Prof Waithaka, Prof Chemining'wa and Prof Hutchinson current chairman.

The study was carried out to compare production, purification and identity of phytotoxins from Exserohilum turcicum isolates of Kenyan, German and Austrian origin. Phytotoxins were extracted from maize leaves inoculated with the pathogen and liquid media seeded with the pathogen isolates. Detection of the phytotoxins was done by checking on inhibition of chlorophyll synthesis using the detached leaf bioassay technique. Thin layer chromatography, high performance liquid chromatography and sephadex columns were used to separate, purify and identify the phytotoxins. Of the 86 isolates used in the study, 48.3% were found to produce phytotoxins either in the liquid media or from the inoculated leaves. The study showed that, a number of phytotoxins including monocerin are produced as indicated by the several peaks and retention times. Maize plants inoculated with the pathogen produced more phytotoxins than the liquid media seeded with the pathogen and each of them had mean lesion sizes of26 mnr' and 14 mm'', respectively. E. turcicum has a high variability in production of different types and amounts of phytotoxins. Maize leaves inoculated with E. turcicum produce more phytotoxins and detached leaf bioassay is a reliable technique in the preliminary detection ofphytotoxins.

Exserohilum turcicum the causal agent of northern corn leaf blight is a threat to corn production in many areas of the world. The pathogen has a high genetic variability in terms of virulence, genetic structure and several races have been reported. Diseased corn plants from Kenya, Germany and Austria were used to isolate the pathogen following the standard isolation procedures. Detached leaf technique using leaves of maize plants with (Ht0) genes for resistance were used to evaluate aggressiveness and the parameters assessed included incubation period, size of chlorotic and necrotic lesions, lesion density, area under disease progress curve (AUDPC) and rate of lesion expansion. Differential cultivars bearing Ht1, Ht2, Ht3, HtN and Ht0 resistance genes were used to perform race typing on 87 isolates under greenhouse conditions. Isolates from the three countries showed a great variation in aggressiveness with incubation periods ranging from 2 to 6 days, lesion size ranging from 1.81 mm2 to 57.04 mm2, rate of lesion expansion ranging from 0.29 mm2/day to 21.67 mm2/day and AUDPC ranging from 31.3 mm2 to 133.9 mm2. Twelve races namely 0,1,2,3,N,12,13,13N,3N,123,23,23N were identified from the three countries. Race 2 was the most common and had 27% frequency of occurrence followed by race 0 and 1 which had frequency occurrence of 22% and 12% respectively. There was no distinct correlation between the type of the race and its origin and different races scattered within the various countries. The high level of genetic variability may explain the occurrence of the disease in the different geographical localities and the ability of the pathogen to infect most of the germplasm including the resistant varieties